1. Field of the Invention
The present invention relates to a magnetic microvalve using a metal ball, and more particularly, to a magnetic microvalve using a metal ball and a method of manufacturing the same that can improve the bonding of upper and lower substrates by locally disposing a PDMS/metal ball combination in a lower substrate, provide quick and easy control by magnetic force, and facilitates the manufacturing thereof.
2. Description of the Related Art
In general, in the area of biochips for biochemical analyses, such as DNA chips or protein chips, and lab-on-a-chips based on microfluidics, flow control techniques are required for the stopping, pumping, mixing, distributing, separating and controlling of the fluidic flow of liquid specimens in microchannels. A wide array of control methods have been proposed therefor.
Here, microvalves serve to stop a flow of micro fluids and perform a flow control thereupon, and micropumps serve to pump micro fluids. There is a correlation between these microvalves and these micropumps in terms of the actuation methods thereof. Microvalves and micropumps employing various kinds of methods have been proposed.
For example, as a method of actuating a micropump and a microvalve, there exist a variety of methods including a microactuating method using mechanical pneumatic technology and the PZT (piezoelectric effect), an EHD (electro-hydrodynamic) technique, such as an electrophoretic method and an electroosmotic method, an actuating method using electrochemical reactions, an actuating method using variations in thermal, optical and electrical properties of paraffin, gel, porous polymers or beads, a capillary flow method using surface tension, a SAW (surface acoustic wave) method, an actuating method associated with body force control using centrifugal force or the Coriolis force, and an actuating method using changes in the optical properties of surface materials or thermal and electrical charges.
As such, a wide array of micropumps and microvalves employing a variety of actuating methods has been proposed. However, micropumps and microvalves in the related art may have complicated actuating methods, manufacturing methods and control thereof, require expensive materials such as silicone, or may be limited in terms of flow and pressure while being actuated.
Furthermore, as for PDMS pneumatic valves or PDMS magnetic valves using PDMS (polydimethylsiloxane) according to the related art, as a PDMS layer needs to be applied over the entire area of a chip, problems may occur when electrodes are installed, when upper and lower substrates are bonded to each other, or when a sample is absorbed.
Therefore, there is a need for microvalves that are easy to manufacture at low cost and provide quick and easy control. In particular, there is a need for microvalves using PDMS that can overcome the above-described disadvantages.